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What Temperature Can Cucumber Seedlings Tolerate

After an unbearably cold winter, when the first warm day of the year rolls around, it can be very tempting to go into full-on spring mode. For some, the first warm day means hitting the outdoors and hiking or taking a bike ride, and for others, it’s getting their hands dirty in their garden. 

However, when it comes to gardening on that first warm day of the year, it actually may not be the best idea. Since winter has such severe temperatures in most climates, your plants will never come to fruition if you rush into planting. This is especially true for vegetable plants, like cucumbers, which are susceptible to growing improperly in cooler temperatures. So, what temperature can cucumber seedlings tolerate?

Cucumber seedlings can tolerate temperatures between approximately 65 to 95 degrees Fahrenheit.

Since cucumber seedlings tolerate temperatures between approximately 65 to 95 degrees Fahrenheit, it’s clear they won’t fare well in the cold. Read on to find out how to protect your cucumber plants in the colder months and what temperatures are the absolute best for them to grow to thief fullest, as well as tips to help your cucumber plants grow to their fullest.

What temperature can you plant cucumbers outside?

Cucumbers can be produced at 65 degrees Fahrenheit, according to Cornell University. While seedlings can potentially tolerate 60 degrees, the ideal planting temperature is 65 degrees or higher. This is precisely why planting your seedlings on that first warm day of the year is a bad idea because the temperatures are likely to vary, which can lead to improper growth or, worse, death.

Can cucumber seedlings survive frost?

No. Cucumber seedlings do not appreciate frost. If temperatures fall below 50 degrees Fahrenheit, seeds usually cannot germinate. Cucumbers can take a brutal hit if frost does happen during their plantation or growth periods. It doesn’t take long for frost to go after your cucumber plant. Frost and the corresponding cold temperatures both have the power to harm or even kill entire cucumber plants. 

Almanac states that you shouldn’t even think about planting cucumber seedlings until two weeks after the final frost, assuming temperatures are above 60 degrees Fahrenheit. Thinking about the temperature is just as crucial as buying suitable soil or ensuring the plant will receive enough sunlight.

See below for the effects of temperatures ranging from below freezing to 85 degrees Fahrenheit on cucumber plants.

Temperature
(listed in Fahrenheit)
Cucumber Plant
Reaction
32 degrees (and under)Harm from frost, Death
33 degrees to 50 degreesStunted growth
51 degrees to 60 degreesNo seed germination
61 degrees to 65 degreesToo cold to plant
66 degrees to 75 degreesPlant outdoors
75 degrees to 85 degreesDesired growth range

The table above shows how poorly a cucumber plant can do in cool temperatures. Anything before 66 degrees isn’t the right time. Rushing into planting in early spring or holding off until consistent warmer temperatures are around can make or break your plant.

Where should I plant my cucumber seedlings?

Finding the perfect place to plant your cucumber seedlings can feel intimidating since they are susceptible to temperature. Finding a sheltered place can help keep the plants warmer and from any frost. This doesn’t necessarily mean you need to have a greenhouse in your backyard. Even a tent or shield above your seedlings can help them prosper.

Soil is also another vital detail to ensure that your cucumber plants grow successfully. According to the Penn State University Extension, “Cucumbers should be grown on soils with good water infiltration rates and moisture-holding capacities.” Taking the extra time to thoroughly research all of your soil options can help you ensure that your cucumbers will grow healthy and will continue to be fruitful for the entirety of the season.

How can I protect my cucumber seedlings?

There are quite a few ways you can help save your seedlings. You can work to protect your cucumber seedlings by utilizing standard cloches, black plastic, or row covers. These work to keep the bad things, like pests and diseases, out of your plant roots and work to keep your cucumbers safe. 

Black plastic offers more than just safety. While it does help keep unwanted pests or diseases away from the cucumber plant root, it can also assist with temperature. The black cover of the plastic absorbs sunlight, which acts as a greenhouse effect, offering additional heat to your plant while it is in its early growth stages.

Other ways to protect your seedlings include starting the plants inside. This helps ensure that your plants are on schedule but aren’t forced to be planted in the ground when the soil may still be too cold for successful growth.

Overall, just taking the time to think about where your cucumber plant will best thrive and the time of year you are planting, and the temperatures you will be exposing the plant to will help you protect your seedlings.

Final Thoughts

Planting vegetables is a great way to spend some time outdoors in the warm months while also producing healthy and delicious food for yourself and your family right in your backyard. To make the most of your cucumbers, learning when and where to plant them can be the difference between a couple of great cucumbers and numerous batches that you can pass on to friends and family.

So, holding off on that first warm day of the year and waiting to plant your cucumber seedlings until spring truly arrives will be best. Waiting for temperatures in the high sixties and planting seedlings in a safe location will set you and your cucumbers up for success. 

Of course, there are additional steps you can take to ensure that your cucumbers remain safe and sound. Paying attention to the soil you plan to plant them in, using covers to help keep unwanted pests away from cucumber plant roots, and proper watering can help your cucumbers be in their prime. Utilizing these tips and tricks will help you go from having a few great cucumbers this year to your best and fullest garden yet.